Mapfile Version
The first non-comment, non-empty, line in a mapfile
is expected
to be a mapfile
version declaration. This declaration establishes
the version of the mapfile
language used by the remainder of the
file. The mapfile
language documented in this manual is version
2.
$mapfile_version 2
A mapfile
that does not begin with a version declaration is
assumed to be written in the original mapfile
language defined for
System V Release 4 UNIX (SVR4) by AT&T. The link-editor retains the ability to
process such mapfiles
. Their syntax is documented in System V Release 4 (Version 1) Mapfiles.